Thank you. Sorry for any confusion. I wasn't questioning member Norman's suggestion. I was curious in general as to the origin and applications of the development of these hybrids in general as an appendum to my original post. (Although now looking back at the thread, I can see why that was confusing. Apologies).
My understanding of synthetic blends. As oil specifications have become more strict, the ability to meet them has become harder to impossible to meet with oils that are primarily Group I or Group II based (mineral). I don't think that Group I has been used a primary base oil in any oil that meets modern specifications for decades. In order to meet modern specifications, "semi-synthetics" use significant amounts of Group III, IV, or V base oils mixed with Group II.
Here is the catch, virtually all oils, including full "synthetics" are a mix of various groups of base oils. The proportions may be different and full "synthetics" will use more Group III, IV, and/or V base stocks which lessens the need for other additives to meet the specifications (i.e. VII improvers, pour point depressants), but at the end of the day, all the oils are a mix of "mineral" and "synthetic" base stocks. It is the higher proportion of more stable "synthetic" base stocks that help full "synthetics" better tolerate high temperatures and perform better over a longer interval.
What does that mean in the real world? Don't get too caught up in what base stocks an oil uses or individual additive components, it tells you little to nothing about its actual performance which is function of the entire package of base stocks and additive package. Look for an oil that meets good approvals, don't get caught up in the brand, and change at regular intervals. In your case, as others have suggested, your engine is very easy on oil and 5,000 mile intervals are conservative. Pick an oil with a good approval (Dexos 1, Gen 3 is a good bar and plenty of oils in the US that meet it), 5w-30 is plenty thick enough, run it, and don't worry about it.